Recent study by Irina Strigo of the University of California San Diego and colleagues showed that individuals suffering from depression react more strongly while anticipating pain.

Researchers found that people with depression had more activity in brain regions involved in emotions when they anticipated or experienced pain.

The study included 15 people in their mid-20s diagnosed with major depression but not taking medication to treat it and 15 similar people without depression.

The study subjects were asked to fill a questionnaires containing questions liker how the depressed group magnified pain, what did it think of it and how did it feel in the face of pain. Then researchers recorded reactions of both the groups when their arms were exposed to heat with the help of functional MRIdefine scanning.

Depressed group showed increased activation in brain circuitry known as the right amygdale, the part of the brain involved in processing emotions, no such stimuli was registered in non-depression participants.

Researchers said that the anticipatory brain response may indicate hypervigilance to impending threat, which may lead to increased helplessness and maladaptive modulation during the experience of heat pain. This mechanism could in part explain the high co-morbidity of pain and depression when these conditions become chronic.

Strigo said: "If a person has chronic pain together with depression, this is a very debilitating condition. This condition is very difficult to treat and the disability is much higher and the cost of treatment is very high."